In passenger transportation environments, it is often necessary to dispose of unwanted fluids and slurries/small solids. Most commercial aircraft and other passenger transportation vehicles are equipped with galley and lavatory sinks, however, these sinks are primarily intended for the disposal of liquid waste only. It is often the case that these sinks terminate at the drain mast of the aircraft (or other vehicle) for exhaustion of the liquids to the atmosphere. This presents multiple challenges. First, when the liquids to be disposed of are dark and potentially staining, such as wine, coffee, and so forth, expelling the liquids to the outside of the aircraft can cause the liquids to “paint” the aircraft sides. This can result in an unsightly streak, staining the aircraft and potentially damaging a “clean aircraft” image and leading to increased maintenance/cleaning cost on the ground. Another problem is that disposing of many liquids to the atmosphere is not environmentally friendly. A further problem is that the lines leading between the sink drain and the drain mast are often small in diameter and if any food particles or slurry material is poured into the sink, it can lead to clogging of the drain line. (Most solids are disposed of in a trash compactor or other waste compartment, but there may be instances where small solids, particles, or granules are combined with liquids to be disposed, and it is desirable to pour unseparated slurry or viscous-like liquids into a sink.) However, traditional sink systems are limited in their ability to dispose of more viscous liquid or particulate waste products.
Some attempted solutions include providing a vacuum galley waste disposal system. These disposal systems function much like an aircraft vacuum toilet. Not only can they dispose of liquid, but they can also flush solid waste. Current systems, however, require an entire disposal system to be installed. They do not use the existing sink space in the galley. Instead, they occupy valuable countertop space inside the galleys. Galley disposal systems also generally include a lid to help reduce sound generated by the vacuum flush. They are manually activated by the user depressing a flush switch or button located near the sink. They also create a somewhat loud flushing sound, which can be a nuisance to passengers seated near the galley. These systems are also similar to toilets in that they typically have a rinse valve/rinse ring incorporated into the basin and require additional fresh water to operate properly.
Improvements to liquid and food disposal in passenger transportation vehicles, such as aircraft, are desired.